Laminated ski having a foam filled honeycomb core



1966 H. M. ANDERSON, JR 3,276,784

LAMINATED SKI HAVING A FOAM FILLED HONEYCOMB CORE Filed May 12, 1965 2 Sheets-Sheet 1 INVENTOR. HENRY mfluoszso Emu P OBE LI A TTORN E i '5 Oct. 4,- 1966 H.'M. ANDERSON, JR

LAMINATED SKI HAVING A FOAM FILLED HONEYCOMB GORE 2 Sheets-Sheet 2 Filed May 12, 1965 Mm N INVENTOR. llcmav Amosesob T HILUP OBEIELIN ATTORN E YS' United States Patent 3,276,784 LAMINATED SKI HAVING A FOAM FILLED HONEYCOMB CORE Henry M. Anderson, In, 6059 Fairhaven, Toledo, Ohio Filed May 12, 1965, Ser. No. 458,824 14 Claims. (Cl. 280-1113) This application is a continuation-in-part of my copending application Serial No. 305,115, filed August 28, 1963, and now abandoned.

This invention relates generally to improvements in skis and, more particularly, is concerned with a novel snow ski construction including a foam-filled metal honeycomb core.

A principal object of the present invention is the provision of an improved ski characterized by its ease of manufacture.

Another object of the invention is to provide a relatively inexpensive snow ski structure yet one which delivers exceptionally high performance.

A further object of the invention is the provision of a ski which is lightweight in construction while still possessing excellent strength and durability.

Another object of the invention is to provide a snow ski having improved internal dampening characteristics.

It is still another object of the invention to provide a ski construction which incorporates a replaceable bottom section.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is a plan view of a ski in accordance with the invention;

FIG. 2 is a longitudinal cross section View taken along the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary perspective view, with certain parts broken away, of a transverse section of the ski;

FIG. 4 is a cross sectional view of the ski taken along the line 4-4 of FIG. 1;

FIG. 5 is a transverse sectional view similar to FIG. 4 except that it illustrates a modification of the invention;

FIG. 6 is a transverse sectional view similar to FIG. 4 illustrating another modification of the invention;

FIG. 7 is a transverse sectional view similar to FIG. 4 illustrating still another modification of the invention; and

FIG. 8 is a transverse sectional view similar to FIG. 4 illustrating a further embodiment of a ski construction in accordance with the invention.

Briefly stated, the present invention provides a ski construction composed of a molded, elongated, resin impregnated fiber glass outer shell and a foam-filled aluminum honeycomb core integrally bonded to the interior surfaces of such shell. Additionally, in accordance with a preferred embodiment of the invention, a bottom or snow contacting member is adhesively bonded to the bottom surface of the shell, which member, due to the novel structure of the ski, may be replaced upon excessive wear thereof.

Referring now to the drawings and particularly to FIGS. 1 to 4, the reference numeral designates generally a preferred embodiment of the new and improved ski. The ski 15 comprises an outer shell indicated generally at 16 (FIGS. 3 and 4) and formed by a generally inverted U-shaped portion 17 and a bottom portion 18, and a core designated generally at 19. The shell 16 is composed of a build-up of layers of impregnated woven glass fiber cloth making the attainment of the desired thicknesses at various points along the longitudinal and transverse axis of the ski Patented Oct. 4, 1966 a relatively simple matter. In this respect, it has been found to be desirable to build up the sides 20 of the inverted U-shaped portion 17 to a greater thickness than the bottom portion 18 or the web 21 of the portion 17 to provide for increased rigidity longitudinally of the ski. The glass fiber cloth is impregnated with a synthetic polymer adhesive such as a phenolic, epoxy, phenolicepoxy, polyester or resorcinol resin.

The core 19, which is enclosed within and bonded to the shell 16, is composed of a foam-filled aluminum honeycomb structure defined by alumi-num Walls 22 which extend vertically from the web 21 to the bottom port-ion 18 of the shell to form a multiplicity of closed, hollow, hexagonal shaped pockets 23. A lightweight synthetic resin foam 24, preferably urethane, completely fills each of these pockets 23, such construction having been found to be easily machineable and provide an extremely effective, strong, vibration-eliminating core. The core 19 extends substantially throughout the length of the ski, terminating slightly inwardly of the end 25, :as indicated at 26, and the tip 27, as indicated at 28.

The core 19 and the bottom portion 18 of the shell are notched, as shown at 29 and 30 respectively, to receive therebetween one leg of hardened steel Z-sections 31 which are adhesively bonded to such core and bottom portion as well as to the lower edges of the sides 20 of the shell portion 17. The steel sections serve in the usual manner of define cutting edges to greatly improve the grip of the ski with the snow, particularly during turns, and additionally serve at the same time to confine the edges of a bottom member or tread facing 32. This bottom member 32 is composed of a material such as cementable Teflon, anodized aluminum, plastic or other substance which provides an excellent sliding contact with the snow and, in accordance with the invention, is bonded to the bottom shell portion 18 by an adhesive layer in such a manner as to be replaceable as will hereinafter more fully be described. The bottom portion 18 of the shell as well as the member 32 are, of course, formed with a guiding groove 33 as is well known and conventional in the art.

In producing a ski in accordance with the invention, a fiat, rigid imperforate member having a length and Width slightly longer than that of the ski core is provided. A foamable mixture of a synthetic resin, preferably urethane, is then applied in a uniform layer to one side of the member, the thickness of such layer being predetermined in accordance with the amount the mixture is known to foam and the density desired of the resulting foam. The resin mixture includes suitable blowing agents which become effective a short time after their incorporation into the mixture, for example, approximately two minutes, to foam the resin.

An aluminum honeycomb skeleton of a length, width .and thickness approximating that of the finished ski but in block form is provided and clamped down upon the resin containing member so that each cavity or hexagonal pocket contains an equal amount of the foamable resin mixture. A second fiat imperforate member is then placed over the aluminum honeycomb and also clamped to the first member, these operations being completed prior to initiation of the foaming reaction. After the foaming cycle has been completed, the two members are removed and the foam-filled aluminum core machined to the exact dimensions desired thereof. The guiding groove 33 is also machined at this time. As previously mentioned, this structure readily lends itself to machining operations making the attainment of any particular shape a simple matter.

A pair of half section metal dies having interior dimensions exactly corresponding to those desired in the 3 finished ski are provided, the bottom die of which is loaded first with a removable spacer insert having theprecise dimensions of the replaceable bottom member 32 and upon wihch a number of layers of resin-impregnated glass cloth is deposited to build up the desired thickness of the bottom portion 18 of the outer shell. The Z-sections 31 are then located, as shown in FIGS. 3 and 4, with a suitable adhesive, for example the same as that employed as the fiber glass impregnant, being applied to the upper surfaces thereof which contact the lower edges of the foam-filled aluminum core 19.

The sides 20 of the U-shaped shell portion 17 are then built-up with the resin-impregnated glass fiber layers to the desired thickness forachieving the proper longitudinal rigidity and thereafter the web portion 21 of the shell also is built-up of such layers. The upper half section of the metal die is then clamped to the lower half section and this assembly heated to cure the resin disposed throughout the fiber glass cloth. In this respect, the resin in the cloth, for example, an epoxy, expands slightly upon heat and cure and penetrates into the foam of the core material thereby effecting a strong and permanent bond between the shell and the core.

Upon completion of the curing cycle, the metal dies are separated and the ski assembly removed therefrom to receive the replaceable bottom member 32. In this connection, an adhesive is applied to one surface of the bottom member which, as previously mentioned, may be composed of cementable Teflon, with the particular adhesive chosen preferably being one which forms a bond that is destroyed at a lower temperature than that at which the shell resin or the adhesive used to'secure the metal Z-sections 31 is rendered ineffective. Thereafter, with the bottom member in place and the adhesive containing side thereof in contact with the bottom portion 18 of the shell, a suitable pressure and/or curing cycle, dependent upon the adhesive, is initiated to form a tightly adhering bond therebetween.

One preferred resin .adhesive system having the above enumerated desired properties employes Bakelite epoxy resin -ERL2772 together with flexible Bakelite epoxy hardener ZZL-0822, both commercially available from the Union Carbide Plastics Company, as the fiber glass impregnant and metal Z-section adhesive. Bakelite ERL-2772 is a monomeric, low molecular weight diepoxide, epoxy resin possessing a high proportion of reactive epoxy groups and is preferably used in the ratio of about 100 parts of resin to 29 parts of ZZL-0822 primary amine-containing Water soluble hardener. This mixture cures satisfactorily at room temperature but ouring time is considerably shortened and properties benefited if heat is added during the curing cycle. After curing, this epoxy adhesive will successfully withstand temperatures of from 325 F. to 400 F. for short periods of time without any ill effect or deterioration.

The adhesive employed in this system for bonding the bottom member 32 to the portion 18 of the shell may conveniently be Shell Epon 1007, a solid bis-epi epoxy resin commercially available from the Shell Chemical Company which possesses a melting point in the range of from 245 F. to 275 F.

With the above discussed type of construction, it has been found that the bottom member 32 may be replaced upon excessive wear thereof without necessitating the loss of the ski as a whole. Thus, it is only necessary that the bottom member be heated to a temperature at which the adhesive layer bonding it to the shell portion 18 is destroyed, for example, 275 F., whereafter it may be easily removed and a new member bonded in its place. With skis now in general use, it is impossible to further utilize them after deterioration of the bottom or snow-contacting portion thereof which often necessitates the buying of new skis, even though the majority of the structure is still in satisfactory condition.

FIGS. 5, 6, 7 and 8 illustrate various other constructions in accordance with the invention where differing degrees of stiffening .are desired, Thus, in FIG. 5, a stiffener 40 which may suitably comprise a bar formed of metal or other rigid material is adhesively bonded in a recess 41 provided in and extending both transversely and longitudinally substantially completely along the upper surface of the foam-filled aluminum honeycomb core 19. The provision of this member increases the bending rigidity, i.e. decreases longitudinal flexing of the ski, to a considerable degree which is advantageous on hard or icy snow.

FIG. 6 illustrates a further embodimentof a ski construction in accordance with the invention which is similar to that shown in FIG. 5 but wherein even slightly greater resistance to longitudinal flexing is achieved. In this embodiment, the bar 40 includes an integral nub ,42 approximately intermediate its width which projects into the foam-filled aluminum honeycomb core and extends throughout the latters length.

The embodiment of the ski in accordance with the in vention illustrated in FIG. 7 is also useful where a greater bending rigidity is desired. In this construction, the inwardly projecting legs of the Z-sections 31 are extended laterally as at 43 and terminate at the guiding groove 33. This novel structure also provides a stronger bottom surface for the ski and is thus useful in situations where a highly rigid snow contacting surface is desired.

FIG. 8 illustrates a further embodiment of the ski in accordance with the invention which is particularly useful where a high degree of torsional rigidity is desirous as well as high bending rigidity. Thus, a rigid U-shaped member 44, which again suitably may be composed of metal, is bonded to the outer surface of the shell portion 17 to terminate just upwardly from the bottom of the sides 20. It will be appreciated that all of the embodiments shown in FIGS. 5 to 8 may be readily produced by following the simple method previously outlined in connection with the ski illustrated in FIGS. 1 to 4, necessitating only minor deviations therefrom to include the various stiffening members.

While, in describing the honeycomb structure, reference has been made exclusively to its being composed of aluminum, it should be understood that it is within the contemplation of the invention .to employ magnesium, aluminum-magnesium alloys and other strong, light metals in this capacity. Aluminum, of course, is a readily available light metal of moderate expense which tends to make its use preferable. Also, while the honeycomb has been described and illustrated as having hexagonal shaped pockets, various other shapes, e.g., triangular, quad-.

rangular, pentagonal, octagonal, etc., may be employed in accordance with the invention.

It is to be understood that the forms of the invention herewith shown and described are to be taken as illustrative embodiments only of the same, and that various changes in the shape, size, composition and arrangement of parts, as well as various procedural changes may be resorted to without departing from the spirit of the invention.

I claim:

1. A ski construction including a molded elongated outer shell composed of a resin impregnated fiber glass cloth build up, and a core integrally bonded to the interior surfaces of said shell, said core comprising a metal honeycomb structure defined by a multiplicity of integrally joined thin walledpockets and a synthetic resin foam filling each of said pockets.

2. A ski construction including a molded elongated outer shell composed of a resin impregnated fiberglass cloth build up, and a core integrally bonded to the interior surfaces of said shell through said resin impregnated in said fiber glass cloth, said core comprising a metal honeycomb structure defined by a multiplicity of integrally joined thin walled pockets and a synthetic resin foam filling each of said pockets.

3. A ski as defined in claim 2, wherein said synthetic resin foam is composed of urethane and said metal honeycomb structure includes hexagonal shaped pockets and is composed of aluminum.

4. A snow ski construction including a molded elongated outer shell composed of a resin impregnated fiber glass cloth build up, a core integrally bonded to the interior surfaces of said shell through said resin impregnated in said fiber glass cloth, said core comprising a metal honeycomb structure defined by a multiplicity of intogrally joined thin walled pockets and a synthetic resin foam filling each of said pockets, and a tread facing member secured to the underside of said shell.

5. A snow ski construction as defined in claim 4, wherein said tread facing member is secured to the underside of said shell through an adhesive bond which is destroyed at a lower temperature than that formed between said core and said shell.

6. A snow ski construction as defined in claim 5, wherein a pair of metal members are provided and extend longitudinally of the ski at either lower side edge of the outer shell to define cutting edges for the ski.

7. A snow ski construction comprising a molded elongated outer shell composed of a resin impregnated fiber glass cloth build up, said shell being formed by an inverted generally U-shaped upper portion defined by substantially vertical side walls and a connecting web, and a flat bottom portion, a resin foam-filled metal honeycomb core integrally bonded to the interior surfaces of said shell, a pair of generally Z-shaped metal sections extending longitudinally of said ski at either side thereof and including a web portion and two legs extending at right angles in opposite directions from either end of said web, said metal sections being bonded to the lower surface of said core, the upper surface of said shell bottom portion and the 'lower edges of the side Walls of said generally U-shaped shell upper portion to define cutting edges for the ski, and a tread facing member secured to the underside of said shell bottom portion.

8. A snow ski construction as defined in claim 7, wherein said metal sections are disposed such that the webs thereof extend vertically between the inner surfaces of said shell side walls and the ends of said shell bottom portion, with the lower leg of each section projecting beneath the said lower edge of the side walls.

9. A snow ski construction as defined in claim 8,

wherein said tread facing member extends between the webs of said metal sections.

10. A snow ski construction as defined in claim 9, wherein said tread facing member is secured to the underside of said shell bottom portion through an adhesive bond which is destroyed at a lower temperature than that formed between said shell and said core and metal sections.

11. A snow ski construction as defined in claim 8, wherein the upper leg of each metal section extends inwardly along the inner surface of the shell bottom portion for a distance slightly less than one half the transverse dimension of the ski.

12. A snow ski construction as defined in claim 7, wherein the upper surface of said core is notched to receive a rigid stifiening member which extends between said shell side walls and is bonded to the undersurface of said upper shell portion connecting web and said core.

13. A snow ski construction as defined in claim 12, wherein said rigid stiifening member is provided with an integral web substantially medial thereof which extends downwardly into said core.

14. A snow ski construction as defined in claim 7, wherein an inverted generally U-shaped rigid stilfening member is bonded to the outer surface of said shell upper portion.

References Cited by the Examiner UNITED STATES PATENTS 2,377,504 6/ 1945 Lermont 280-11.13 2,428,979 10/ 1947 May 156-197 2,728,702 12/1955 Simon et a1 280-11.13 2,866,730 12/1958 Potchen et al 280-11.13 2,908,506 10/ 1959 Runton 280-11.13 2,928,456 3/ 1960 Potchen et a1 280-11.13 3,201,138 8/1965 Brown 280-11.13 FOREIGN PATENTS 214,326 3/ 1961 Austria.

215,868 6/1961 Austria.

572,337 3/ 1959 Canada.

985,174 3/1951 France. 1,262,624 4/1961 France. 1,299,263 6/ 1962 France.

BENJAMIN HERSH, Primary Examiner.

MILTON L. SMITH, Examiner. 

1. A SKI CONSTURCTION INCLUDING A MOLDED ELONGATED OUTER SHELL COMPOSED OF A RESIN IMPREGNATED FIBER GLASS CLOTH BUILD UP, AND A CORE INTEGRALLY BONDED TO THE INTERIOR SURFACES OF SAID SHELL, SAID CORE COMPRISING A METAL HONEYCOMB STRUCTURE DEFINED BY A MULTIPLICITY OF INTEGRALLY JOINED THIN WALLED POCKETS AND A SYNTHETIC RESIN FOAM FILLING EACH OF SAID POCKETS. 